Methods for high temperature etching a high-k gate structure

Abstract

Methods for etching high-k material at high temperatures are provided. In one embodiment, a method etching high-k material on a substrate may include providing a substrate having a high-k material layer disposed thereon into an etch chamber, forming a plasma from an etching gas mixture including at least a halogen containing gas into the etch chamber, maintaining a temperature of an interior surface of the etch chamber in excess of about 100 degree Celsius while etching the high-k material layer in the presence of the plasma, and maintaining a substrate temperature between about 100 degree Celsius and about 250 degrees Celsius while etching the high-k material layer in the presence of the plasma.

What is claimed is: 
     
         1 . A method of etching a high-k material, comprising:
 providing a substrate having a high-k material layer disposed thereon into an etch chamber;   forming a plasma from an etching gas mixture including at least a halogen containing gas into the etch chamber; and   maintaining a substrate temperature between about 100 degree Celsius and about 250 degrees Celsius while etching the high-k material layer in the presence of the plasma.   
     
     
         2 . The method of  claim 1 , wherein the high-k material is selected from a group consisting of hafnium dioxide (HfO 2 ), zirconium dioxide (ZrO 2 ), hafnium silicate oxide (HfSiO 4 ), hafnium aluminum oxide (HfAlO), zirconium silicate oxide (ZrSiO 4 ), tantalum dioxide (TaO 2 ), aluminum oxide, aluminum doped hafnium dioxide, bismuth strontium titanium (BST), and platinum zirconium titanium (PZT). 
     
     
         3 . The method of  claim 1 , wherein the high-k material is hafnium aluminum oxide. 
     
     
         4 . The method of  claim 1 , wherein supplying the gas mixture further comprises:
 supplying a chlorine containing gas into the etch chamber.   
     
     
         5 . The method of  claim 4 , wherein the chlorine containing gas includes at least one of BCl 3 , and Cl 2 . 
     
     
         6 . The method of  claim 4 , wherein supplying the chlorine containing gas further comprises:
 supplying a carbon hydrogen gas with the chlorine containing gas into the etch chamber.   
     
     
         7 . The method of  claim 4 , wherein supplying the chlorine containing gas further comprises:
 supplying an inert gas with the chlorine containing gas.   
     
     
         8 . The method of  claim 1  further comprising:
 maintaining an interior surface of the etch chamber at a temperature in excess of about 100 degrees Celsius while etching the high-k material layer in the presence of the plasma. 
 
     
     
         9 . A method of etching a high-k material, comprising:
 providing a substrate having a metal gate electrode disposed on a high-k material layer formed on the substrate into an etch chamber;   etching the metal gate electrode layer to form a trench exposing the high-k material; and   etching the high-k material through the trench by a halogen containing gas at a temperature between about 100 degrees Celsius and about 250 degrees Celsius.